Consumers have come to expect a glossy, aesthetic exterior finish on new vehicles, such as automobiles and boats. Similar expectations also exist in the aftermarket industry, where vehicles undergo repairs after the exterior of the vehicle has been damaged. Yet achieving a truly aesthetic finish can be daunting. The eye is extremely keen in its ability to spot even the slightest surface defects, which in turn degrade the finish. Manufacturers and repair shops thus demand rigorous systems and methods capable of removing substantially all surface defects to gain customer acceptance. These systems and methods generally use a wide array of specialized abrasive applications.
For example, a typical automotive exterior repair job is a multi-step process involving a series of abrasives having progressively smaller and smaller grain sizes. In a typical procedure, a portion of the panel of an automobile to be repaired is first sanded using a coarse abrasive layer that fully removes any pre-existing paint from the metal surface. The surface is then cleaned and then coated with a suitable body repair material, such a body filler, putty, epoxy resin, or urethane resin. Examples of these body repair materials are described in PCT Application Nos. WO2008115648 (Janssen et al.) and WO2008076941 (Janssen et al.).
Once hardened, the repair material is sanded so that it is flush with the surrounding surface using a progression of abrasives. The sanded area is then coated with a primer layer, typically using a spray gun. After the primer layer is dry, a suitable abrasive is then used to sand the primed surface. The primed surface is then cleaned, and, optionally, surrounding panels are scuffed and a base coat applied with a color that generally matches the rest of the vehicle. A transparent clear coat is then applied over the entire surface of any panels to which base coat was applied. An appropriate abrasive is then used to remove defects such as dirt nibs, dust particles, or excessive orange peel texture. A set of abrasives and/or polishing compounds are then used to remove any sand scratches from the clear coat, and to restore a glossy finish.
There is substantial value to the practitioner in conducting the repair or finishing process as efficiently and as economically as possible. It is further desirable to avoid introducing defects to the workpiece in any of the operations described above. Removal of defects inadvertently introduced by the practitioner can add considerable time to the finishing process.